1. Field of the Invention
The present invention relates to combined connectors, having mixed grounded and non-grounded contacts and to connectors with shielding.
2. Description of the Prior Art
Nakajima, in U.S. Pat. No. 4,974,075, discloses a connector with a coaxial arrangement of contact pins (62b) and mating sockets (81a) which engage the pins when the two parts of the connector are joined by relative motion in the axial direction. The pins are laid out in two concentric circles, one inside the other, to form two radial groups of contacts. The contacts are of the insulated type, with their conductors surrounded by plastic.
Nakajima provides shielding with a tubular or annular-cylindrical metal shield around the entire connector and another shield in between the inner and outer groups of contacts; the various parts fit together like telescope tubes, with alternating metal and plastic. Thus, electrical contacts belonging to the inner and outer circles are shielded from one another, but there is no shielding between contacts both belonging to one of the two radial groups of concentric contacts, which are separated only by plastic. There is nothing to prevent cross-talk within a radial group of contacts.
Another drawback of Nakajima""s arrangement is mechanical weakness. The cylindrical annular plastic portions, in which the pins and sockets are embedded, have walls of minimum thickness because the interfitted metallic shields create extra bulk. The metal shielding pieces are relatively thin, too, for the same reason. If the assembled connector is subjected to a bending stress the interfitted annular cylindrical portions of the connector are liable to warp, making it difficult to separate and rejoin the two halves of the connector.
Each of Nakajima""s mating connector halves uses expensive constructions, such as large-diameter threads and shoulder stops. Such large threads are not only expensive, but difficult to join.
The Nakajima arrangement is unsuited to connectors including ground contacts. For example, it would be difficult or impossible to adapt to a plurality of coaxial cable conductor pairs, or to shielded conductor pairs.
One object of the present invention is a connector that combines grounded lines in a single connector, for example, combining a coaxial cable with grounded outer conductor with a plurality of shielded conductor pairs.
Another object is a connector which is mechanically strong and tough.
Still another object is a connector which can simultaneously join triaxial, twinaxial, and/or coaxial cables and join their grounds at the same time.
The present invention provides a conductive, preferably solid metallic, insert or connector body for connecting a plurality of grounded cables, these being in addition to the usual non-grounded lines or cables typically found in the middle of a military-style (or other) connector. The insert comprises two mating annular cylinders each of which preferably fits into one half of a standard connector housing. Bores run longitudinally through the assembled connector body from end to end, and meet at the junction between the two cylinders. The cable couplings are held in each of the two cylinders with retention clips, so that the couplings mate when the two cylinders are mated.
Because the insert is conductive it provides an ideal common ground to which each of the grounded cable grounds can be coupled, and it also provides a Faraday shield around the coupling of each cable, to limit cross-talk. A common electrical connection exists among the two cylinders and the grounds of the cables. If the connector housings are metallic, a second electrical connection between each of the cylinders and its respective housing is preferably made as well. Staking is the preferred method of making this connection.